Overview

My solutions written in Golang, Java and Kotlin for Advent of Code 2020.

Disclaimer

Note that this code is hacky, not polished or refactored in any way, i.e. it is probably the worst spaghetti code you can imagine. Its sole purpose was to solve the puzzles, it should not be used as example for good code. That means, after I retrieved the correct solution for a puzzle, I left the source code as it is without any cleanup. Or stated otherwise, I intentionally gave myself the permission to hack around...

Day	Problem	Topic
1	Report Repair	Simple equation solving
2	Password Philosophy	Implement validation parser
3	Toboggan Trajectory	Geometrical analysis on an infinite grid
4	Passport Processing	Solve logic puzzle with interdependent variables
5	Binary Boarding	Solve a SAT-based problem
6	Custom Customs	Interdependent boolean expressions
7	Handy Haversacks	Parse and compute recursive expressions
8	Handheld Halting	Simulate simple CPU with self-modifying code
9	Encoding Error	Numeric puzzle with large number of inputs
10	Adapter Array	Computing and processing large number of permutations
11	Seating System	Mixture of cellular automata and general 2D geometry
12	Rain Risk	Simulate ship movements and relative computations
13	Shuttle Search	Number theory (chinese remainder formula)
14	Docking Data	Bitwise binary computations
15	Rambunctious Recitation	Game simulation with intelligent caching
16	Ticket Translation	Set-based combinatorial puzzle solving
17	Conway Cubes	Simulating a 3D conway cube
18	Operation Order	Parsing mathematical expressions
19	Monster Messages	Parsing a BNF grammar
20	Jurassic Jigsaw	Tile matching of a split and randomized image. This was probably one of the most difficult puzzles I've ever solved in AOC.
21	Allergen Assessment	Breadth-First solver for pattern matching
22	Crab Combat	Modulo-based array arithmetic
23	Crab Cups	Circular linked list operations
24	Lobby Layout	Cellular automata in a hexagonal grid
25	Combo Breaker	Public key cryptography